Hermann hirsch



Unire sfrn'rns HERMANN HIRSCH, OF BERLIN, GERMANY.

CONSTRUCTION OF SHIPS.

Specification of Letters Patent No. 25,198, dated August 23, 1.859.

To all 'whom t may concern:

Be it known that I, HERMANN HIRscH, of Berlin, in the Kingdom ofPrussia, Germany, have invented a Normal Vessel; and I do hereby declarethat the following is a full, clear, and exact description of the same,reference being had to the annexed sheet of drawings, making a part ofthe same.

The special peculiarity of this new invention is its entirely removingthe possibility of breakage of the keel (known as breaking back) inships and imparting to the bottom a normal form giving a maximum ofsteadiness without retardation of velocity.

The description of this form of ship, its comparison with those hithertoin use and the account of its peculiar advantages are the objects of thefollowing remarks.

1. Descm'pton.

The inventor takes a plane horizontal surface, (Plate II Figure l)bounded by two arcs a. f Z) and a g b. The chords of these two equalarcs give the. longer axis a Z) bearing the proportion to the shorteraxis g of 27?; to l0. A circular aperture d, Zt, c i is made in theplane the diameter of which stands in the proportion to the shorter axisg, f of 1 to 4. This aperture allows of the plane surface being curved(or folded or bent) in such a manner as to give the peculiar form of thenew ships bottom. The semi axis l (L is first bent downward and then thesemi axis Z) e upward, the folding or bending being confined within twolimits. The diameter of the circular aperture will of course becontracted by this bending or folding such contraction b-eing within thelimits of 1g and of Zt Fig. 2, Plate II, gives a view of the interior orupper part of the plane so folded. a d is the semi axis folded downwardall the letters having the same value as in Fig. l z' is the contracteddiameter of the aperture.

Fig. 3 gives a view of the exterior or under part of the plane a Zappearing above and e b below.

On referring to Fig. Q. it will be at once evident that the semi axis eZ) retains no position parallel with its former one, but rises somewhattoward Z)-a Z retaining a position parallel with that which itoriginally occupied. In Fig. 3 e Z) is depressed toward Z), c dremaining parallel. In Fig. 4 this is evident. a Z is horizontal, c brises in such a manner that Z) e can be produced in a right line to a.This rising is essential and theref fore constant. If the curving orfolding be proceeded with in conformity with this principle so that thediameter of the aperture ZL, z', is diminished to one-fourth.

Fig. 4 gives us a view (in elevation) of the starboard side of the hull(bottom). The diameter of the opening ZL z' being reduced the diameterci e becomes increased, but as half of the curvature proceeds upward andthe other half in the opposite direction the semi circle indicated inFig. l by the letters Z z' e assumes, when seen from the side the figureof an S as shown in Fig. 4. Further as the longer axis given in Fig. las a right line a b appears in Fig. 4, after the folding or curvature,horizontal in the semi axis a d and elevated in e Z) the arc a g b inFig. l must also assume the form of the letter S in Fig. 4. Fig. 4compared with Fig. 2 will now render the mode of shading the drawing soas to give the appearance of a solid clear, the point g in Fig. 4 lyingsideward under e.

It will be seen from this statement that the bottom consists of fourparts viz. two aft and two forward. The Figs. 2, 3 and 4 together showthe two after parts in the upper or interior portion convex, and in theunder or exterior, concave decreasing in size aft toward the keel andbecoming broader amidships. Both portions meet at the keel each moreforward part however retaining its own special independent properties(details). Each assumes a compound curvature downward which may be seenin Fig. 4 projected on the longitudinal section of the ship from e toZ). As however the sem1- axis rises obliquely each fore portion of thebottom becomes curved obliquely toward the lower part of the ship. Inproportion as the folding is effected with greater or lesser contractionof the diameter of the aperture h Fig. l, the arcs a. g and g Z) becomemore or less elevated or depressed, thus imparting a proportionateflatness or sharpness to the bottom of the ship. Fig. 4 fw w shows theaverage water line. 0n the bottom thus formed a bulk head rising fromthe keel upward is now erected the after part of which forms the sternpost, the lower extremity the keel and the part bent forward, the stemand the head Fig. 4 la Z. The partition appears at a d undisturbed fromd.

It intersects the foreward half of the hull, .and at cl Z b appears asstem and head the two fore portions joining the keel-partition at e b.

The aperture for the screw in screw vessels is to be introduced at fw.This keel partition can be carried upward at pleasure and whether it isto be subdivided in serving as junction for the two longitudinalsections of the ship or whether it be intersected by oblique and otherbulkheads and made subordinate. to the purposes of the hold depends uponcircumstances.

Comparison 07E this form of mZZ wit/"f,

those /w't/wrto a use.

This comparison must be confined to the chief requisites of a ship viz.,firnmess, steadiness, capacity and velocity or speed.

l. The firmness which is imparted to the whole construction is soevident that urther discussion of it is unnecessary. It is of courseincreased when other partitions perpendicular or oblique to itareintroduced and the liability of breaking back is thus removed; and asit is unnecessary to continue the keel bulk-head into the upper portionsof the hull (above the hold) the hatchways may be of any size required.In all the constructions hitherto used the only safeguard against suchbreakage was afforded by the clamps, wales water ways and carlines.

2. Steachncss-The steadiness which the whole mass acquires by means ofthe new and peculiar bottom is increased nearly threefold, the t-wopartially separated curvatures of the fore part taken together wi'th thegreat want of depth of the hold toward the waist form a mutual supportto the two forward portions and to the whole of the after-hold soV muchso that it may be asserted and proved, partly by calculation and partlyby numerous experiments, that a ship provided with such a hold acquiressuch steadiness of motion as to require no ballast. The samepeculiarities secure the vessel against pitching and rolling.

Capacite/. The capacity (for the accommodation of cargo) of a vesselbuilt with such a bottom can complete with that of the bestconstruc'tions hitherto employed. Firstly, because the greater possiblefreedom is offered in the choice of the form of the part of the shipabove water the new bottom being taken as a foundation. Secondly becausethe length of this bottom gives a proportion to the breadth of beamseldom attained by the present, often exaggerated, efforts to attaingreat length.

L Velocity/. The velocity or speed attainable with the new bottom may beseen from the following important peculiarities, The opposing mass ofwater is divided by the keel-bulk-head and thrown two curves formingtoward the whole of the fore part of the ship which are curved nearly in`the form of a cone and lie obliquely. Impinge ing on these surfaces,thus inclined and thus curved, the water must be thrown off with aminimum of impulsive force. Affording a striking contrast to thehitherto almost perpendicular rise of the bows and fore part of theship. Further, the hollow form of the after part of the hold sinking andbecoming' sharper aft shows with what force the water flowing along thetwo sides toward the rudder endeavors to reunite imparting to the shipan uncommon facility in steering and clearly an increased rate of speed.

These advantages being considered together it will be seen what a savingin time and fuel is effected by a ship having this form of bottomcombined with the centrifugal screw invented by the same individual.

A singular addition to the above-named advantages is presented by acontrivance by which the. ship may be arrested while at full speed andbrought to instantaneous rest, and by which also a side motion from thepoint may be communicated to the ship at pleasure an advantage which thepresent and increasing danger of collision or fouling must render ofthehighest importance for merchant ships as well as for the evolutions ofwar steamers. This contrivance consists of a species of fin attached tothe keel-bulkhead which in the usual progress of the vessel remains inthe same direction as the keel and of which two may be used together orseplrately at a greater or less angle with the kee Fig. is added toPlate II for further elucidation, it gives Fig. t in an invertedposition. The letters for reference have the same value in both.

Having now described the nature of my said invention and in what mannerthe same is or may be performed, I wish it to be distinctly understoodthat I do claim as my invention- The form and construction substantiallyas herein set forth of the hull of ships or vessels, whereby thepossibility of breakage of keel is removed and a normal form giving amaximum of steadiness without retardation of velocity is imparted to thebottom.

HERMANN HIRSCH.

Witnesses:

Y. H. F. PRILLWITE, C. LEHMANN.

